<!doctype html>
<html lang="en">

<head>
    <!-- Required meta tags -->
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
    <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@4.4.1/dist/css/bootstrap.min.css">
    <style>
        .box {
            background: url(srbg.jpg) no-repeat;
            width: 100%;
            height: 100vh;
            background-size: cover;
        }
        
        .row {
            position: relative;
        }
        
        .biaodan {
            width: 430px;
            height: 349px;
            position: absolute;
            left: 50%;
            top: 130px;
            background: rgba(144, 217, 255, 0.3);
            padding-top: 30px;
            box-sizing: border-box;
        }
        
        .controls {
            display: inline;

        }
        
        .biaodan .denglu {
            width: 400px;
            height: 50px;
            margin: 10px auto;
            line-height: 50px;
            font-size: 28px;
            color: #4FFFFF;
            text-align: center;
        }
        
        .tt {
            padding: 15px 50px;
            color: #fff;
            font-weight: 700;
        }
        .control-group{

        }
        .cor{
            width: 100%;
            text-align: center;
        }
        .btn {
            width: 30%;
            margin: 10px auto;
            background: rgba(79, 255, 255, 0.3);
        }
    </style>
</head>

<body>
    <div class="box">
        <div class="container">
            <div class="row">
                <div class="biaodan col-xs-12">
                    <div class="denglu">登录</div>
                    <form class="form-horizontal">
                        <div class="control-group tt">
                            <label class="control-label" for="inputEmail">用户名:</label>
                            <div class="controls" style="margin-left: 20px;">
                                <input type="text" id="inputEmail" placeholder="用户名" style="width: 230px;">
                            </div>
                        </div>
                        <div class="control-group tt">
                            <label class="control-label" for="inputPassword">密码:</label>
                            <div class="controls" style="margin-left: 35px;">
                                <input type="password" id="inputPassword" placeholder="密码" style="width: 230px;">
                            </div>
                        </div>
                        <div class="control-group">
                            <div class="cor"><button type="submit" class="btn btn-primary">登录</button></div>
                        </div>
                    </form>
                </div>
            </div>
        </div>
    </div>
    </div>

    <script src="https://cdn.jsdelivr.net/npm/jquery@3.4.1/dist/jquery.slim.min.js"></script>
    <script src="https://cdn.jsdelivr.net/npm/popper.js@1.16.0/dist/umd/popper.min.js"></script>
    <script src="https://cdn.jsdelivr.net/npm/bootstrap@4.4.1/dist/js/bootstrap.min.js"></script>
</body>

</html>